Re: Jupiter (was PERIHELION etc.)

[Bernard Cleyet <anngeorg@PACBELL.NET>]

Ok, here's the skinny:

I 'phoned Dr. Bodenheimer * (UCO Lick).  He says:

~ 10% is g contraction (as JM suggested!)  and ~ 90% primordial
(accretion and initial contraction).  As GK pointed out, and I wrongly
discounted, the outer atmosphere is insulating.  PB in our long
conversation stressed this.

Another calc. I'd like to do, but must stop:

Given the surface is ~ 100deg. K, the interior ~ 20K deg. K,  and the
various dimensions; calculate the average R value.  This will be off
somewhat, as the 10% energy from present contraction is not likely in
the core.


He also said there's lots published and should find some on the web.

"... But the mass of the planet is about ten
times smaller than what would be needed
to start thermonuclear burning."

PB says more like 60. (If I remember correctly.)




* http://www.ucolick.org/~board/faculty/bodenheimer.html
<http://www.ucolick.org/%7Eboard/faculty/bodenheimer.html>


bc



Ludwik Kowalski wrote:

> Jupiter radiates into space more "heat" than
> it receives from the Sun. How can this be
> explained? According to:
>
> http://www-astronomy.mps.ohio-state.edu/~pogge/Ast161/Unit6/jupiter.html
>
> "Jupiter radiates about 2.5x more energy at
> Infrared wavelengths than it receives from
> the Sun. . . .  Jupiter is slowly contracting
> under its own weight. Slow contraction
> releases gravitational energy, heating the
> deep interior."
>
> I have no doubt that the radiation difference
> (emitted versus received) is an experimental
> fact. But what evidence do we have that the
> planet is still undergoing slow contraction? Is
> this only a hypothesis (what else can it be?)
> or is it a fact based on observations?
>
> It seems to me that the rate of contraction
> would be too small to measure. Yes, the
> liquid metallic hydrogen (below the thick
> atmosphere) should be a good conductor
> of heat and electricity. But this does not
> explain the origin of conducted heat.
>
> By the way, the percentage of hydrogen
> in Jupiter is nearly the same as in the Sun.
> But the mass of the planet is about ten
> times smaller than what would be needed
> to start thermonuclear burning.
> Ludwik Kowalski